<template>
 <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div  @mouseenter="mouseenterTit" @mouseleave="mouseleaveTit">
        <h2 class="all">全部商品分类</h2>
        <transition name="nav">
        <div class="sort" v-show="isShow">
          <div class="all-sort-list2" @mouseleave="currentIndex = -1">
            <div
              class="item"
              v-for="(category, index) in categoryList"
              :key="category.categoryId"
              :class="currentIndex === index ? 'active' : ''"
              @mouseenter="throttleEnter(index)"
              @click="gotoSearchHandle"
            >
              <h3>
                <a
                  :data-category1Id="category.categoryId"
                  :data-categoryName="category.categoryName"
                  >{{ category.categoryName }}</a
                >
              </h3>
              <div class="item-list clearfix">
                <div class="subitem">
                  <dl
                    class="fore"
                    v-for="child in category.categoryChild"
                    :key="child.categoryId"
                  >
                    <dt>
                      <a
                        :data-category2Id="child.categoryId"
                        :data-categoryName="child.categoryName"
                        >{{ child.categoryName }}</a
                      >
                    </dt>
                    <dd>
                      <em
                        v-for="item in child.categoryChild"
                        :key="item.categoryId"
                      >
                        <a
                          :data-category3Id="item.categoryId"
                          :data-categoryName="item.categoryName"
                          >{{ item.categoryName }}</a
                        >
                      </em>
                    </dd>
                  </dl>
                </div>
              </div>
            </div>
          </div>
        </div>
        </transition>
        
      </div>
      <nav class="nav">
        <a>服装城</a>
        <a>美妆馆</a>
        <a>尚品汇超市</a>
        <a>全球购</a>
        <a>闪购</a>
        <a>团购</a>
        <a>有趣</a>
        <a>秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import _ from "lodash";
import { mapState} from "vuex";
export default {
  name: "NavType",
  data() {
    return {
      currentIndex: -1,
      isShow:false
    };
  },
  mounted() {
  //节流
    this.throttleEnter = _.throttle(this.mouseenter, 30, {
      leading: true,
      trailing: false,
    });
     //3.初始化的时候判断当前的路径,决定是否展示三级列表
    this.isShowUpdate();
    
  },
  methods:{
      //鼠标移入让三级列表展示和高亮
        mouseenter(index){
        // console.log(111)
            this.currentIndex = index
        },
         gotoSearchHandle(e){
         const params = this.$route.params
         //事件委托，判断如果是a标签，就跳转到search
           if(e.target.nodeName==="A"){
                const query ={}

                const {category1id,category2id,category3id,categoryname} = e.target.dataset
                query.categoryName = categoryname 
                if(category1id){
                    query.category1Id = category1id
                }else if(category2id){
                    query.category2Id = category2id
                }else if(category3id){
                    query.category3Id = category3id
                }
                // console.log(query,"222");
                this.$router.push({
                    name:"search",
                    query:query ,
                    params 
                })

           }
           },
       //当为home时 默认展示一级列表  
     isShowUpdate(){
     if (this.$route.path === "/home") {
        this.isShow = true;
      }
     
     },
     //除了home组件其他组件需要移入全部商品分类再展示一级列表
     mouseenterTit(){
     if(this.$route.path === "/home") return
        this.isShow = true;
     },
      mouseleaveTit() {
      if (this.$route.path === "/home") return;
      this.isShow = false;
    },
  },
  computed:{
        ...mapState("home",["categoryList"])
    },
  watch:{
  //在点击三级列表选择时，希望三级列表隐藏，展示后面的页面，所以监听路由的改变，当改变时就设置为false
    $route:{
      handler(){
        this.isShow =false
      }
    }

  }
};
</script>

<style lang="less" scoped>
.nav-enter,
.nav-leave-to{
  opacity: 0;
}
.nav-enter-active,
.nav-leave-active{
    transition:all 0.3s linear
}
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &.active {
            background:navajowhite;
            .item-list {
              background:honeydew;
              display: block;
            }
          }
        }
      }
    }
  }
}
</style>